Marine vessels including multiple hulls can include suspension for locating and controlling the position of at least one of the hulls relative to the chassis or body portion. For example, U.S. Pat. No. 7,314,014 discloses a water craft having a body portion suspended above four hulls, each hull being located relative to the body portion by a single wishbone suspension linkage arrangement.
U.S. Pat. No. 5,228,404 discloses a trimaran where the chassis is supported above three hulls, each being movable relative to the chassis. The three hulls comprise a left hull, a right hull and a rear central hull, all three hulls being interconnected by a lateral bar about which they are individually pivoted. The rear centre hull has two laterally spaced rearward trailing arms and a forwardly spaced central trailing arm, all three trailing arms being parallel and having substantially the same length to maintain the rear centre hull horizontal relative to the chassis, since the rear centre hull also contains the propulsion means for the vessel. The front and rear of each of the laterally spaced (left and right) side hulls has a respective support arrangement. Each front and rear support arrangement comprises a long lateral arm between the chassis and the respective side hull and a short lateral arm between the chassis and the centre of the long lateral arm. The chassis end of the long lateral arm can slide along lateral tracks on the chassis acting against a spring and damper, the respective arrangement thereby providing resilient, damped support of the chassis above the respective end of the respective hull together with maintaining the lateral location of the side hull under the chassis mounting position of the short lateral arm.
U.S. Pat. No. 9,272,753 discloses a catamaran having a suspension geometry of a front leading arm and a rear slider for each hull to provide the required lateral, longitudinal, yaw and roll location of the respective hull relative to the chassis or body portion, leaving the hull free to move in the heave and pitch modes relative to the chassis. Heave motions relative to the chassis of the left hull in an opposition direction to the right hull is the roll mode of the suspension system. Similarly pitch motions relative to the chassis of the left hull in an opposite direction to the right hull is the warp mode of the suspension system.
However with such marine vessels having a chassis or body portion at least partially suspended relative to multiple hulls, regardless of whether the chassis engages the water or not, there is a design compromise in the width of the vessel between the hulls being laterally spaced wide apart for passive roll stiffness and the hulls being laterally spaced close together to make the vessel footprint narrow for negotiating confined spaces such as ports or marinas and/or for transportation on a trailer.
The trimaran disclosed in U.S. Pat. No. 4,730,570 has left and right hulls mounted on cross beams that can be moved laterally to vary the beam (i.e. the track or width) of the vessel, but without changing vessel height and without providing for any suspension motion to accommodate resilient supports.
The catamaran in U.S. Pat. No. 5,277,142 uses pairs of upper and lower unequal length lateral swing arms to reduce the width or beam of the vessel by swinging the left and right hulls under the chassis, which raises the chassis while reducing the track or lateral spacing between the side hulls.
In U.S. Pat. No. 8,408,155 the left and right hulls are also not able to move resiliently relative to the chassis, but are mounted to the chassis by swing arms to enable the chassis to be raised to improve the clearance of the chassis to the waves. However, the lateral spacing between the hulls is decreased when the chassis is raised, which is an undesirable combination for stability. Chinese registered utility model number 201999173 discloses a similar arrangement where each side hull of a catamaran is fixed to a swing arm that rotates relative to the chassis to both raise the chassis and decrease the lateral spacing between the hulls, or conversely to lower the chassis and increase the lateral spacing of the hulls and the vessel width. Both of these two inventions lower the vessel centre of gravity and simultaneously widen the spacing between the left and right hulls for improved stability when operating at speed. However vessel speed can be limited by wave impacts, so the rougher the sea state the larger the requirement for the height under the chassis.
Japanese patent application publication number 2002193181 discloses a planing type high speed vessel which has a chassis or body portion supported above hydrofoils resiliently mounted on the ends of extending rams or linkages to enable the height of the body portion above the hydrofoils to be increased. As the height of the body portion is increased relative to the hydrofoils, the width (i.e. lateral spacing) between the hydrofoils also increases. However there is only one suspension locating linkage for each hydrofoil to locate it relative to the body portion which does not provide a strong control of the yaw of the hydrofoil relative to the body portion.